A spectrometer is a device which receives a light signal as an input and produces as an output a light signal which is spread out, or dispersed, in space according the different wavelength components, or colors, of the input light signal. A detector attached to the spectrometer can analyze the output signal, called the spectrum, to quantify the amount of each wavelength component that is present in the input signal.
A specific type of spectrometer is known as an Offner spectrometer which can be used to produce images of a remote object over a contiguous range of narrow spectral bands. This type of imaging is known as hyperspectral imaging and has recently emerged as an important part of the military/aerospace solution to airborne and spaceborne reconnaissance and remote sensing. Basically, a hyperspectral imaging system which includes fore optics, an Offner spectrometer, a detector, and an advanced data processing technology is able to produce imagery of a scene of interest (remote object) with embedded spectral signature data. This signature data is useful in a wide-variety of applications such as target designation/recognition, missile plume identification and mine detection (for example).
In addition, the hyperspectral imaging system can be used in a wide-variety of commercial applications as well like cancer detection, environmental monitoring, agricultural monitoring and mineral exploration (for example). Because, the hyperspectral imaging system is important to military, aerospace, and commercial industries, manufacturers have been actively trying to develop new and better ways to make and improve the performance of the Offner spectrometer. For instance, the co-assigned U.S. Pat. No. 7,697,137 B2 (the contents of which are incorporated by reference herein) discloses a hyperspectral imaging system that includes a monolithic Offner spectrometer that was an improvement over the traditional Offner spectrometers. Although, the monolithic Offner spectrometer associated with the '137 patent works well in many applications it is still desirable to develop a new monolithic Offner spectrometer. A hyperspectral imaging system that incorporates a new monolithic Offner spectrometer and several methods for manufacturing the new monolithic Offner spectrometer are the subject of the present invention.